The Daily Telegraph reported that this is particularly relevant for those holidaying in Guernsey, Jersey, Alderney, Sark and Herm, as these islands have ended an agreement with British authorities over healthcare cover.

Steve Williams, head of travel insurance at Confused.com, explained that the absence of the card could result in medical bills totalling "thousands of pounds".

He told the national newspaper: "Travellers should ensure they not only have the right travel insurance, for their circumstances, but they have read the policy in detail - especially when claiming medical expenses."